Two figures of merit commonly associated with DC-DC switched mode power converters, particularly point-of-load (PoL) converters, are power density (typically measured in W/m3), and power efficiency (defined as the ratio between Power out and Power in). PoL converters are used close to electronic loads such as micro processors, FPGAs, DSPs and memory. They find widespread use in infrastructure applications, such as telecommunications, data communications, data centres, server farms and the like. Power efficiency is important, to reduce undesirable heating close to the load, and to reduce resistive losses of the typically high currents (which can be tens of amps), through routing (for instance PCB tracks) from the converter to the load; power density is important to limit parasitic interconnecting inductances, so as to enable higher frequency switching of the converter and thereby use of smaller passive components.
It is known that, in the dimensioning of components for DC-DC converters, anticipated operational characteristics have to be taken into account: these include not only the steady-state operational currents and voltages, but also non-steady-state currents and voltages which may be encountered under transient conditions. It is not uncommon to encounter currents which exceed the normal steady-state maximum current by 30 to 40% during a transient condition such as the sudden switching in or switching out of a load to the converter. Components such as inductors and output capacitors therefore have to be dimensioned appropriately
There is an ongoing requirement for control methods which suppress such transients, but which do not have a negative impact, or have only a reduced negative impact, on converter's power efficiency